Low power laser in the prevention of induced oral mucositis in bone marrow transplantation patients

Abstract

6541 Background: High-dose chemotherapy followed by bone marrow transplant produces undesirable effects in the oral cavity leading to oral mucositis (OM) that may be a painful and debilitating side-effect. Laser therapy has been used to improve the symptoms and duration of already established OM in this group of patients (pts). Recent data suggest the upfront use of laser therapy may decrease the incidence of OM. Methods: Through the use of upfront LPL as protecting and modulating therapy of the oral mucosa membrane, we evaluated the potential for a reduction in the incidence and/or severity of OM in pts submitted to autologous (AT) or allogeneic (AL) bone marrow transplant (BMT). Sample size was based on estimative of P0 control = 0.6 and a P1 LPL = 0.1, β = 0.1; α= 0.05. From Jan 2004 to May 2005, 38 pts treated at the National Bone Marrow Transplant Center in Rio de Janeiro were randomized into a group of 19 pts that received and a group of 19 that did not receive the application of the preventive LPL from the beginning of the conditioning. The irradiation was used an diode InGaAlP, emiting light at 660 nm wavelenght with output power of 50 mW, giving an energy density of 4 J/cm2. The tip of the laser device touched the oral mucosa. The evaluation of OM was done by different investigators both by WHO and OMAS scale. Results: The male to female ratio was 60.5/39.5%. The median age 37 (19–56). The frequency of AT and AL was 73.7 (15.8% non related) vs 26.3%. In the LPL group 94.8% of pts had OM WHO grade < 2 (including 63.2% with grade 0), whereas in the control group 68.4% of pts had OM grade III and IV (p<0,001). Remarkably the HR for grade II, III and IV OM was 0.41 (CI 95% 0.22–0.75, p = 0,002) and for grade III and IV was 0.07 (CI 95%0.11–0.53, p<0,000). Using OMAS scale by the calculation of ulcerous area, 73.6% of LPL pts presented lesions of 0 to 3 cm2, whereas 73.6% of the control group presented ulcers from 9.1 to 18 cm2 (p=0.003). An agreement was observed among investigators (index of 81.7%) and between WHO and OMAS scale (p<0,001). Conclusion: Our results indicate that the use of upfront LPL in bone marrow transplantation patients is a powerful instrument in reducing the incidence of OM and is now standard in our center. No significant financial relationships to disclose.